Comparative study of direct injection analysis and liquid chromatography mass spectrometry for identification of chemical constituents in Kudiezi injection by FT-ICR MS

In order to evaluate the performance of direct injection analysis (DIA) and liquid chromatography-mass spectrometry (LC-MS) with ESI-FT-ICR MS on identification of chemical constituents in traditional Chinese medicines (TCMs), Kudiezi injection was selected and analyzed as a sample by both methods. The discovery and identification capacities of two methods were compared, and MS/MS experiments were also carried out to identify chemical constituents. Except 5 components were not detected by DIA FT-ICR MS, other 42 chemical constituents were all tentatively identified by both methods, including phenolic acids, nucleosides, flavonoids and sesquiterpene lactones. It indicated that FT-ICR MS was suitable for identification of chemical constituents in TCMs. And DIA FT-ICR MS had comparable identification capability to LC FT-ICR MS but consumed only 2 min of the analysis time. Therefore, DIA FT-ICR MS could be recommended to be a fast identification strategy for TCMs, while LC FT-ICR MS could be necessary when comprehensive screening and identification of chemical constituents in TCMs. (C) 2016 Published by Elsevier B.V.